@mixin set-topline($c: #c7c7c7) {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 1px;
    border-top: 1px solid $c;
    color: $c;
    transform-origin: 0 0;
    transform: scaleY(.5);
}

@mixin set-bottomline($c: #c7c7c7) {
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    width: 100%;
    height: 1px;
    border-bottom: 1px solid $c;
    color: $c;
    transform-origin: 0 100%;
    transform: scaleY(.5);
}

@mixin set-leftline($c: #c7c7c7) {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    width: 1px;
    height: 100%;
    border-left: 1px solid $c;
    color: $c;
    transform-origin: 0 0;
    transform: scaleX(.5);
}

@mixin set-rightline($c: #c7c7c7) {
    content: '';
    position: absolute;
    right: 0;
    top: 0;
    width: 1px;
    height: 100%;
    border-right: 1px solid $c;
    color: $c;
    transform-origin: 100% 0;
    transform: scaleX(.5);
}

@mixin set-roundline($c:#c7c7c7, $border-radius: 0) {
    content: '';
    position: absolute;
    width: 200%;
    height: 200%;
    border: 1px solid $c;
    transform: scale(.5);
    transform-origin: 0 0;
    border-radius: $border-radius;
    top: 0;
    left: 0;
    box-sizing: border-box;
    border-right: 0;
}